dquakeplus/source/libpspmath/vfpu_quaternion_sample_hermite.c
2022-02-08 16:49:56 -05:00

67 lines
1.7 KiB
C

#include "pspmath.h"
// constants for the hermite curve functions
ScePspFMatrix4 hermite = {
{ 2, -3, 0, 1 },
{ -2, 3, 0, 0 },
{ 1, -2, 1, 0 },
{ 1, -1, 0, 0 }
};
void vfpu_quaternion_sample_hermite(ScePspQuatMatrix *qout, ScePspQuatMatrix *a, ScePspQuatMatrix *b, ScePspQuatMatrix *at, ScePspQuatMatrix *bt, float t) {
__asm__ volatile (
// load hermite transform matrix
"lv.q C000, 0(%6)\n"
"lv.q C010, 16(%6)\n"
"lv.q C020, 32(%6)\n"
"lv.q C030, 48(%6)\n"
// load a, b, at, bt
"lv.q C100, 0(%1)\n"
"lv.q C110, 0(%2)\n"
"lv.q C120, 0(%3)\n"
"lv.q C130, 0(%4)\n"
// C200 = [ t^3, t^2, t, 1]
"mtv %5, S202\n"
"vmul.s S201, S202, S202\n"
"vmul.s S200, S202, S201\n"
"vone.s S203\n"
// multiply M000 by C200
// C000 = [ 2*t^3, -3*t^2, 0, 1]
// C010 = [ -2*t^3, 3*t^2, 0, 0]
// C020 = [ t^3, -2*t^2, t, 0]
// C030 = [ t^3, -t^2, 0, 0]
"vmul.q C000, C000, C200\n"
"vmul.q C010, C010, C200\n"
"vmul.q C020, C020, C200\n"
"vmul.q C030, C030, C200\n"
// sum the terms
// S210 = 2*t^3 - 3*t^2 + 1
// S211 = -2*t^3 + 3*t^2
// S212 = t^3 - 2*t^2 + t
// S213 = t^3 - t^2
"vfad.q S210, C000\n"
"vfad.q S211, C010\n"
"vfad.q S212, C020\n"
"vfad.q S213, C030\n"
// scale the qaternions with terms
"vscl.q C100, C100, S210\n"
"vscl.q C110, C110, S211\n"
"vscl.q C120, C120, S212\n"
"vscl.q C130, C130, S213\n"
// sum the results
"vadd.q C100, C100, C110\n"
"vadd.q C100, C100, C120\n"
"vadd.q C100, C100, C130\n"
// and return results
"sv.q C100, 0(%0)\n"
:"+r"(qout): "r"(a), "r"(b), "r"(at), "r"(bt), "r"(t), "r"(&hermite));
}